1. Field of the Invention
The present invention relates to a method and apparatus for providing high resolution color images using xerographic and thermal ink jet technology and more particularly, to an annotator for adding additional information to copies wherein the annotator is a low cost color thermal ink jet printer.
2. Description of Related Art
As known to those skilled in the copier arts, it is often necessary to add certain information such as instructions, caveats, names, addresses, and the like to copies being produced by a copier or reproduction machine. This information, which does not appear on the original image, is usually placed in some non-image area, typically the copy margin.
Known references which form composite images include U.S. Pat. No. 4,167,324 which discloses a technique whereby a latent image of an original document is formed on a photoreceptor by a light lens system along a first optical path while a modulated light beam input is directed along a second optical path to the surface of a belt. The belt provides a charge pattern on a previously formed latent image in conformity with information in the modulated laser input.
U.S. Pat. No. 4,385,822 discloses formation of a composite image whereby an electromagnetic recording medium is used to form a first electrostatic latent image in one layer thereof, and a second magnetic latent image in a second layer thereof.
IBM Technical Disclosure Bulletin, Vol. 22, No. 12, May 1980, pp. 5270-5271 discloses a composite image forming technique whereby a latent electrostatic image of an original is formed by a light/lens optical system. At a downstream position, an ion writing station deposits a selected charge pattern on an already discharged portion of the latent image.
U.S. Pat. No. 4,774,546, assigned to the same assignee as the present invention, discloses an apparatus for forming a composite image comprising an annotator including an illumination source, an addressable light modulation device such as a liquid crystal panel and a lens array for forming a modulated light pattern onto a photosensitive surface.
U.S. Pat. No. 4,551,0080 assigned to the same assignee as the present invention, discloses an image annotator having an array of flexible light reflecting fingers individually actuatable to create an annotated image within borders of a copy image.
U.S. Pat. No. 5,038,218 discloses an image processing assembly which combines digital copier image data and electronic data from an external source, stores the combined data in a memory, performs resolution and orientation conversions, and prints out the combined images utilizing a single printer.
These prior art techniques are subject to various problems and suffer from various disadvantages. The laser modulated systems are very expensive and require significant space. The ion generator and electromagnetic techniques are costly to implement and require stringent alignment procedures. These techniques do not allow color annotating, without use of a color copier since both images are formed on a belt surface of the copier by charging or recharging portions of the surface and developing by the copier. Additionally, these usually require discharging the photoreceptor belt in portions where the annotated data is to be placed, followed by recharging of the portions prior to imaging of the annotated data. None of the prior known art provides a high-quality, low cost color annotator which utilizes thermal ink jet printing technology to provide color annotating and color composite images irregardless of the type of xerographic system used.
Thus, there is a need for a low cost annotator capable of color image printing which can be utilized with a copier or duplicator to provide a high-quality composite image onto a copy sheet. Additionally, there is a need for a low cost annotator which includes the advantages of thermal ink jet printing.